This invention relates to wear and heat resistant steel alloys.
With recent strong requirement for preventing air pollution by the exhaust gas from internal combustion engines adapted to be mounted on vehicles, particularly motor cars, large efforts have been made to use fuels (gasoline) not containing a lead compound and to increase the temperature of combustion which is necessary to assure perfect combustion of the fuel. This increases the temperature of the exhaust gas thereby increasing the damage to valves and valve seats caused by the exhaust gas, which is a serious problem to be solved quickly in the art of internal combustion engines. Heretobefore valve seats have been made of copper alloy castings, cast iron, sintered alloys, heat resistant steel, etc. An alloy SUH.sub.4 specified by JISG-4311 has also been used frequently. But the damage caused by the attempts for reducing pollution is too serious and any satisfactory solution has not yet been made.